1, spread by water
Plants that grow in or near water usually spread their seeds by water power, such as coconuts and water lilies.
Coconut: when the fruit of coconut tree is ripe, its shell is hard and hard, like a boat. After falling from the tree, it drifted away with the sea. When the tide washes it onto the island, new coconut trees will grow on the shore.
Water lily: When the fruit of water lily matures, it will fall into the water and slowly rot. Seeds covered with spongy exocarp will float on the water surface, drift with the current, and finally sink to the bottom to take root and sprout.
2, spread by birds or other animals
If you walk in the grass, many plant seeds or fruits will stick to clothes or trousers, or to other animals, or animal food, such as undigested seeds of birds, will be excreted and even taken to further places, such as Bidens bipinnata, Ficus, Plantago and so on.
Cherry, wild grape, wild ginseng: Birds or other animals eat seeds in their stomachs, but because they can't be digested, they are discharged with feces and spread in all directions.
Pine nuts: They were taken away by squirrels when storing winter grain. Pine nuts, hazelnuts and walnuts: In autumn, squirrels like to take these nuts away and bury them underground or in tree holes for preservation. Some of them will take root and sprout in the burial place before being eaten in spring.
3, spread by the wind
Some seeds or fruits will grow hair or wing-like structures, which will float far away when the wind blows, such as dandelion, blackboard tree, Showa grass and so on.
Hongliu: It is the flying catkins that spread seeds far away. In spring, catkins fly everywhere. Do you know the mystery of catkins flying in spring? Grab a group of catkins and observe carefully, and you will find some small particles inside, which are willow seeds. Willow spreads its seeds far away through flying catkins.
Dandelion: The achene of dandelion in compositae has many long crown hairs. When it matures, these crests spread like parachutes, flying with the wind and spreading the seeds far away.
Extended data:
How to improve the germination rate of seeds is very important in the propagation of flowers and trees. If this step is not done well, it will seriously affect the unearthed rate of seedlings and cause unnecessary economic losses. The following are the technical points of seed treatment of flowers and trees.
1. Sun-drying: If the seeds are collected by yourself, they must be sun-dried before sowing (but never exposed to the sun), which can effectively improve the vitality, germination rate and germination potential of the seeds. Germination rate refers to the proportion of seed germination, and germination potential refers to the proportion of germination per unit time. If the flowers and trees seeds are repurchased in the market, this step can be omitted, because the seed company will definitely do this step.
2. Seed soaking: The purpose of seed soaking is to promote the early germination of seeds and kill some eggs and viruses. From a professional point of view, for flowers and trees with hard seed shells, hormones are also needed for seed soaking, such as lavender and cyclamen. For others, it is not necessary to soak seeds with hormones. The soaking time depends on the instructions for hormone use. It is suggested to use expert gibberellin to promote seedlings.
3. Accelerate germination: This step is the most critical. The family recommends using a transparent glass, soaking it with a layer of paper towel and laying it on the bottom of the glass, putting the seeds evenly on the paper towel, and then laying a layer of soaked paper towel. Then seal the cup with plastic paper. Then wait for germination. (The germination time varies from 2 days to 15 days, depending on the germination period of seeds)
4, matters needing attention in the process of germination
Temperature: Pay attention to keep the temperature at a suitable temperature.
Humidity: Before germination, the paper towel must be kept moist, that is, the seed germination humidity should be kept.
Others: transplant the seeds as soon as possible after germination to avoid damaging the root system.
Seed is the most important part of planting, and good planting is the basis of high yield and income increase. Seed selection is very important. Select the seeds of regular seed enterprises, try planting first, test the adaptability of local seeds, and then plant them in a large area to resist planting risks.
You can also search the client of planting sub-database, and inquire about major domestic seed companies and various seed varieties. At the same time, you can apply for an agent, try planting for free or buy seeds directly at the factory price to see the planting effect in various regions. You can search for planting sub-libraries in major app stores.
The seeds of general plants consist of seed coat, embryo and endosperm. The seed coat is the "armor" of the seed and plays a role in protecting the seed. Embryo is the most important part of seeds, which can develop into roots, stems and leaves of plants. Endosperm is the place where seeds concentrate nutrients, and the endosperm of different plants contains different nutrients.
During the development of embryo and endosperm, the volume of embryo sac expands continuously, which destroys nucellar tissue outside embryo sac and is finally absorbed by embryo and endosperm. So there is no nucellar tissue in mature seeds. However, some plants retain nucellar tissue during seed development and store nutrients to form exoendosperm. Mature seeds of spinach, beet and coffee have exoendosperm. The mature seeds of pepper and ginger have both endosperm and exoendosperm.
References:
Baidu encyclopedia-seed